Pneumatic action for typewriters and other multiple key devices



April 30, G w CARLSQN PNEUMATIC ACTION FOR TYPEWRITERS AND OTHER MULTIPLE KEY DEVICES Filed March 10, 1936 5 Sheets-Sheet 2 lly'roR April 30, 1940. G. w. CARLSON PNEUMATIC ACTION FOR TYPEWRITERS AND OTHER MULTIPLE KEY DEVICES Filed March 10, 1936 5 Sheets-Sheet 5 r 4 I I4? Q n I R mm W rill/ 7 April G. w. cARLsoN 2,198,860

PNEUMATIC ACTION FOR TYPEWRITEHS AND OTHER MULTIPLE KEY DEVICES Filed March 10, 1936 5 Sheets-Sheet 4 -7 I ll r 32 26 $1 9.5. -27

INVENTOR 4- Z4 M g m 4 *fi April 30, 1940. 3, w CARLSQN 2,198,860

PNEUMATIC ACTION FOR TYPEWRITERS' AND OTHERMULTIPLE KEY DEVICES Filed March 10, 1936 5 Sheets-Sheet 5 Patented Apr. 30, 1940 UNITED STATES PATENT OFFICE George W. Carlson, Pittsburgh, Pa., assignor to Robert H. McGlintic; Pittsburgh, Pa.

Application. March 10, 1936, Serial No. 68,068

, 15 Claims.

This invention relates to a pneumatic key operating action for use in selectively operating the keys of typewriters or other devices having a plurality of elements adapted to be selectively moved through the control of a record sheet.

While the present invention will be described herein particularly as a pneumatic action for typewriters, it will be understood that instead of using a typewriter, otherdevices having a multiplicity of keys or levers may be used in place of a typewriter.

At the present time, pneumatic actions are provided for typewriters, the actions being provided with a record roll mechanism and a tracker bar. The movementof a perforated record sheet over the tracker bar causes the mechanism to operate the keys of a typewriter. The mechanisms heretofore used for this purpose have been in all essential respects a duplication of the basic mechanism used in player piano actions. In all such actions, there is provided a separate pneu- I matic for each key on the typewriter. Each pneumatic is connected through a motion transmitting connection with the key of the type- 35 writer which it is designed to operate. The collapse of the pneumatic under the control of the record sheet provides the power for operating the key. There are in excess of'forty keys on a standard typewriter in addition to the shift and 30 tab keys, and installations as heretofore provided require a pneumatic for each key and each pneumatic must be capable of furnishing the power required to operate the key. This number of pneumatics requires a considerable amount of space. In addition, it requires a vacuum pump of considerable capacity. In addition to this,

. the rods which transmit motion from the pneuvmatics to the keys must be individually installed and tensionedso that the keys will be operated with equal force. Each of these several pneumatics in installations of the type now generally used requires a separate valve unit for controlling it, each valve unit including a primary and. a secondary valve.

According to the present invention, a substantially diiferent pneumatic action is provided which requires considerably less space than actions heretofore used for the purpose, which re- 50 quires a considerably smaller vacuum pump, which eliminates the requirement of a separate pneumatic for operating each key and the requirement for a separatexvalve unit for each key, and which further avoids the use of any con- I; nections which have to lie-individually tensioned position merely for the purpose of illustrating or adjusted to equalize the touch or force applied to each key. 7

According to the present invention the power for operating all of the keys is derived from a single pneumatic unit. There is provided a pneumatic selecting mechanism controlled by the tracker bar and record and which brings connections attached to the several keys selectively into engagement with this operating unit. The

' selector mechanism is extremely simple and compact and is of a type which requires no valves.

In pneumatic actions as heretofore commonly employed for the purpose of operating typewriters and like instruments, it has been the practice to employ flexible diaphragms commonly known in the art as pouches. These diaphragms have been used to actuate valves and the valves in turn have been used' to control the action ofpneumatics, and the pneumatics have transmitted power to the keys to be operated. With the present invention, the pouches themselves function as the operating part of the selector unit, materially simplifying the arrangement and eliminating a very considerable number of valves.

Not only is the mechanism of the present invention much more simple and more compact, but because of the simpler and smaller volume of the pneumatic circuits, the action is speedier and is quicker and snappier, most of the cause for sluggishness which exists in present pneumatic actions being eliminated.

The invention may be readily understood by reference to the ccompanying drawings, in which Figure 1 represents a longitudinal vertical section through a pneumatic mechanism embodying my invention and showing the same connected to a typewriter, the typewriter being more or less schematically illustrated;

Figure 2 is a more or less schematic view showing the pneumatic action in side elevation, certain parts, however, being broken away, the view showing the tracker bar in a purely arbitrary the pneumatic circuit;

Figure 3 is a plan view of a portion of a modified form of tracker bar;

Figure 4 shows a pneumatic circuit for that portion of the mechanism which transmits power to the typewriter or other keys to be actuated and showing the adjustable control through which the force at which the keys are operated can be adjusted, the View showing the parts detached from their actual location in the machine, as

but connected to illustrate the pneumatic circuit;

Figure 5 is a section through the pneumatic valve action for controlling the member which transmits motion to the keys, which member is hereinafter called the rocker bar, the view being on a larger scale than the corresponding parts in Figure 4;

Figure 6 is a top plan view of the selector unit also referred to in this specification as the pouch box", the cover of the box being removed;

Figure 7 is a perspective view of a single section of the selector or pouch box detached from the box assembly; 1

Figure 8 is a transverse section through one of the pouch units, the view being on an enlarged scale;

Figure 9 is a more or less schematic view showing the pneumatic circuits for the shift and tab keys of the typewriter, these being arranged for operation independently of the system which employs the pouch box;

Figure 10 shows in side elevation at part of the mechanism shown in Figure 7, illustrating the connection between an operating pneumatic and a tab and the shift key;

Figure 11 is an edge elevation of one of the connectors which attaches to the typewriter or other lever to be actuated and which serves to transmit motion from the rocker bar to the key; and

Figure 12 is a side elevation of this connector.

Referring to the drawings, 2 designates a supporting frame for the pneumatic actuating mechanism, this framehaving a portion 3 providing a support for a typewriter or other implement having a plurality of keys or levers to be actuated. 4 designates a standard typewriter having a plurality of keys or key levers 5. The keys 5 represent the usual type and space bar keys as distinguished from the shift key and the tab key. The keys 5 have the usual portions 6 which extend horizontally from the keyboard under the forward part of the frame of the machine and serve to transmit motion to the type bars. The construction of the typewriter per se forms no part of the present invention. and in place of the typewriter there may be substituted any other device having a plurality of keys or levers to be operated selectively as, for example, a perforating punch for making records for automatic typewriters. A

Attached to the horizontal portion 6 of each key 5 is a connector I. These connectors, which are shown in detail in Figures 11 and 12, are formed of strip metal. They are provided at their upper ends with a resilient clip portion la so constructed that the connector member can be inserted up between the key bars 6 of the typewriter and then pulled down and clipped over the respective key bars. The connectors l are provided at their lower ends with a laterally turned hook portion 117. The only mechanical connection between the typewriter keys and the pneumatic actuating mechanism is provided through these connectors 1. As above indicated, they can be quickly snapped into position,'1'equiring no special skill or no special machining operations on the typewriter. When the several connectors l are snapped onto the keys; they are arranged in line across the width of the machine and they are of the same length so that the terminal portions lb all terminate in substantially the same horizontal plane. The resilient clip In the drawings, particularly Figure 1,

portion Ia at the top of each connector allows these connectors 1 to pivot so that they may be swung through a limited are from right to left as viewed in Figure 1.

' Attached to each connector I is a connecting link 8, the connecting link 8 having a terminal portion 8a which makes a pivotal connection with the member I and having at its other end a terminal portion 81) providing a friction coupling for engagement with a horizontally extending operating rod 9.

Supported in the frame 2 for up and down motion adjacent the terminals lb of the connectors l, is a transverse bar i0 hereinafter referred to as a rocker bar". In the operation of the machine embodying the present invention, the rocker bar is moved up and down. The rods 8 are successively operated at a time when the rocker bar is at the upper limit of its movement to pull a selected one of the connectors I toward the left, as viewed in Figure 1, so that as the rocker bar l0 moves down, the terminal hook portion lb of that connector which has been so moved to the left will be engaged by the rocker bar and the key to which that connector is attached thereby depressed. With the upward movement of the rocker bar the connector 1 which has been so engaged to depress a key is released and returns to its normal position. The rocker bar is preferably moved by one or more pneumatics.

In the present invention, I have shown the rocker bar H] as being secured to the movable tops ll of two downwardly collapsible pneumatics i2, as best shown in Figure 4. When the pneumatics it are collapsed. the upper leaves ll pull the rocker bar l0 down to effect the operation previously described. Two separate pneumatics are employed in preference to a single large pneumatic in order to give a more uniform support and for a more even operation of the rocker bar. I have shown light U-shaped springs at l3 for pushing the rocker barback to its normal position after it has been depressed by the pneumatics.

The pneumatic mechanism comprises, in addition to the rocker bar and its operating pneumatics, a suction pump unit A, a valve box B, a valve unit C for the rocker vbar pneumatics,

a selector mechanism D for selectively operating the several rods 9, and a tracker barE with its associated record sheet reels. or pouch box unit'D and the rocker bar pneumatics are preferably controlled by perforations in a record sheet moving over the tracker bar. The tracker bar designated as 15 is of conventional form, having a plurality of holes or openings therein, the number of holes depending on the number of keys to be selectively operated and the number of functions to be performed by the machine, as is well understood by those familiar with pneumatic actions. Leading from each active hole in the tracker bar is a tube connection. In Figure 1, I 6 designates the winding reel and- H is the record reel, and in the normal operation of the machine the record X moves in the direction of the arrow shown in Figure 1, until the end of the record has been reached, when the reeling operation is reversed to rewind the record. In the rewinding of the record. the record is moved at a higher speed that in its normal forward operation, and during this rewinding it is, of course, not desired that any of the typewriter keys or the rocker bar be actuated.

Any known record winding or rewinding Both the selector mechanism may be employed and the particular mechanism is. therefore, not shown. I prefer, however, to use the record drive shown in my copending application Serial No. 68,071, filed March 10, 1936.

The selector mechanism or pouch box D will next be described. The pouch box or selector unit is an assembled construction comprised of a plurality of cross strips 20 between which are spacers 2|, the construction being assembled by means of staggered screws as illustrated at the right hand side of Figurefi. All joints are packed with fiber and with a relatively weak adhesive so as to make an air-tight construction but one which can. when necessary, be taken apart for purposesof repair. The box is providedwith an air-tight cover 22.

Each cross strip is provided with a number of separate pockets 23. Leading into each pocket through the bottom of the strip is a passage 24 and each passage 24 is provided with a metal tubular elbow 25 to which a hose or tube connection can be made.. Each one of these pockets 23 isalso provided at its top with a small open ing 26 into which is set. a small metal cup 26',

this cup having a very small orifice 26 in the bottom thereof, the cup 26' with its orifice coin prising what is termed in the pneumatic art a bleeder cup. It serves. to establish restricted communication from the interior of the pocket 23 to the interior of the box construction. Across each pocket 23 is a leather diaphragm 2'! (see Figures 2 and 8). The passage provided by the passageway 24' opens to one side of this pouch or diaphragm. The other side of the diaphragm is exposed to the pressure or vacuum that exists inside the box.

Forming a sealing gasket between successive sections 2U--2i are thin flexible members 28.

preferably made of leather. (see Figure 7), which clearly shown in Figure 7. Secured to each of the fingers 29 is a rigid fiber or wooden strip 30. This may be glued to the leather member 29. The strip 30 extends from the top .of the finger down across the pouch. but terminates slightly above thelowermost portion of the leather finger, leaving a slight reach or portion 29a which is not reinforced by the rigid element. The arrangement is such that when the air pressure in the chamber 23 back of the pouch or diaphragm is greater than the pressure inside the pouch box. which condition exists if the interior of the pouch box is connected to a vacuum pump and atmospheric air is admitted through the passage 24, the pouch or diaphragm 21 will be forced out wardly. The button 21a carried on each diaphragm or pouch presses outwardly against the finger 29 tending tomovethe member 30 outwardly or to the left, as viewed in Figure 8. The portion of leather 29a provides a hinge that permits such free movement of the fingers 29-30.

There is provided a light spring 3| for return ing the flngersto their normal position when they are pressed outwardlyin the manner described. These springs may comprise nothing more than a piece of spring wire. having one end embedded in the body of the cross piece 20 and having one end embedded in or bearing against the strip 30. They are set diagonally as shown in Figure 7. Each one of the rigid strips or fingers 30 is provided with a stiff leather tab .in number to the number ofpouches inside the pouch box. The strip 33 is set tightly against the front of the box so as to seal this slot except for the openings which are provided therein. This strip 33 is in turn provided with spacers 34 which hold a second strip 35 the strip 35 having openings therein registering with those in. the strip 33. The arrangement is such that the rods 9 attached to the connectors 8 for the several keys pass through the openings in the strips ,35 and 33 and extend into the pouch box. The inner ends of these rods 9- are threaded and the threaded portions are passed through the holes in the tabs 32. The rods 9 have a close working fit within the holes in the strips 33 and 35, particularly the strip 33, so that there is practically no leakage of air or only a'very limited leakage of air from the atmosphere through the holes in the strip 33 to the interior of the selector or pouch box. By reason of the fact that the strip 33 and preferably also the strip 35, are made of graphite bronze. the sliding fit between the rods 9 and the holes can be very close without there being any detrimental friction. By reason of the fact that the pouches are staggered in the manner previously described. all of the rods 9 are in a single plane and are side by side as shown in Figure 6.

Each one of the elbows or connectors 25 for the several pouches is provided with a rubber tube leading tothe proper opening in the tracker bar. In Figure 1. for the purpose of simplicity. only two of these rubber tubes have been shown. and in Figure 2. which shows a typical circuit diagram, only a single hose leading from a pouch in the selector D to the tracker bar is illustrated. These hoses or rubber tubes are designated 36.

At the rear of the pouch box unit D is an outlet connection 3'! to which is connected a tube 38 leading through a connection 39 to. a valve casing B. From the valve casing B there is a tube 40 leading to the exhaust or vacuum pump unit A. For the purposes of the present descripof which is to cut oil" the suction from the vacuum 7 pump to the interior of the box D when the record is rewinding. The details of the particular cutoff valve form no part of the present invention. although one such type of valve will be hereinafterdescribed in connection with the rocker bar pneumatic circuit.

The vacuum pump A may be of any. suitable character. It is preferably of the type having a number of collapsible bellows M with an exhaust valve at 42 and an intake valve at 43. the bellows being operated through connecting links 44 from the throws 45 of a crank shaft 46. The motor which drives the winding and rewinding mechanism may also operate this crank shaft. the driving mechanism not being shown in the present application but being illustrated inmyc said copending application Serial No. 68,071, filed March 10, 1936.

In the operation of the machine with the record X moving in the direction of the arrows shown in Figures 1 and 2, the record closes the several openings in the tracker bar against the entrance of air therethrough. The vacuum pump exhausts the air from the interior of the pouch box or selector unit. When an opening such as the opening a in the record X moves over an appropriate tracker bar opening, air will pass from the atmosphere through the record through the tracker bar opening into the tube 316. This will create a differential pressure on the pouch with which the tube 36 communicates, as evident -from an inspection of Figure 2. When atmospheric air is admitted to the rear of the pouch with suction existing in the pouch chamber, the pouch tends to bellow outwardly or move to the left as viewed in Figures 2 and 8. This transmits motion to the finger "29-30, rocking this finger toward the left. A corresponding pull is exerted on the attached rod 8; This pull is transmitted through the resilient connector 8 to the connector bar I depending from the typewriter key bar, causing the portion lb of the connector I to be projected into the path of travel of the rocker bar. When'the rocker bar is depressed, the corresponding .key will be actuated. As soon as the opening a. in the record has moved past the opening in the tracker bar, further atmospheric air to the rear of the pouch will be cut off and such air as was admitted will be exhausted through the bleeder cup 26'26" into the interior of the pouch box. When the rocker bar ceases to press against the hook portion of the connector I, the

spring 3I will function to move the rod 9 towardthe right as viewed in Figure 2, and restore the parts to their normal position.

It will thus be seen that the selector mechanism for all of the keys is embodied in a relatively small pouch box. All of these pouches operate without the use of valves of any kind'. A very simple pneumatic circuit, therefore; selectively controls the operation of the typewriter or other keys.

It will now be apparent that there should be a very slight time lag between the actuation of one of the pouches to set one of the connectors I, and the instant when the rocker bar I starts to move down because if these two operations occurred simultaneously, the rocker bar might fail to properly engage the hook on that connector I which has been actuated. The present invention, therefore, contemplates that the actuation of the rocker bar also be under the control of the record sheet. The rocker bar and its accompanying pneumatic circuit will next be de-' scribed. I

I have previously pointed out that two pneumatics I2 are preferably employed to operate the rocker bar. The control of these pneumatics is effected through an opening in the record sheet. Referring to Figures 4 and 5, there is disclosed the valve arrangement through which the operation of the rocker bar pneumatics is efiected. Each of the pneumatics I2 has an opening 56 at the bottom thereof communicating with a passage 5| leading to' a valve chamber 52 in the valve unit C. In the valve unit C, there -is a small chamber 53. This chamber has leading thereto a tube or connection through which air is exhausted from it, the tube 54 comprising part of a circuit to be hereinafter traced, leading to the vacuum pump A. In the chamber 53 are two diaphragms or pouches 55 for operating valves 56. Between the two valves 56, which are known in the art as secondary valves, is a primary valve 51 attached to a third pouch 58. A bleeder cup 58 establishes communication from the rear of the pouch 58 to the main vacuum chamber 53. Leading from the rear of the pouch 58 is a passage 60 to which communicates a rubber hose or tube 6i leading to an appropriate opening in the tracker bar I5. The primary valve 51 is shown in Figure 5 as being in its seated position, in which-position port 62 is sealed against the entrance of atmospheric air. Leading .from the port 62 are passages 63 through- .hold the pneumatics open or expanded. -When opening b (see Figure 2) moves over the appropriate opening in the tracker bar I5, atmospheric air is admitted to the tube H and back of the diaphragm or pouch 58 for the primary valve. This allows the primary valve to drop so that atmospheric air can enter the passages 63 into the chamber under the pouches 55. Since there is a vacuum or reduced pressure in the chamber 53 above these pouches, the pouches will be bellowed upwardly, actuating the valves 56, moving these valves 56 up so that the tops of these valves cutoff the passage for atmospheric air entering through the ports 64. At the same time the lifting of these valves 56 establishes communication from the chambers 52 through the ports 52a (around the valve extensions) into the vacuum chamber 53. When this occurs, air is exhausted through the port 50, passage 5|, chamber 52 and chamber 53 and pipe 54, causing the pneumatics I2 to collapse against the tension of the springs I3 thereby moving the rocker bar.

As soon as the opening b has passed the opening in the tracker bar, atmospheric air is cut oil from the tube '6I, air is exhausted from back of the diaphragm 58 through the bleeder cup 59, and the primary valve 51 is closed. Atmospheric air below the pouches iswithdrawn through the passages 63 into the port or passage 62 and thence' to the chamber 53, whereupon the pouches 55 drop, restoring the secondary valves 56 to their normal positions, admitting atmospheric air to the pneumatics I2 and allowing them to expand. This entire operation takes place almost instantaneously.

As before stated, it is desirable to have a slight time lag between the operation of one of the selector pouches and the corresponding movement of the rocker bar. This time lag is procured in either of two very simple ways. In Figure 2 it will be noted that the hole b for operating the rocker bar is just slightly behind the hole a for operating a key pouch in reference to the awaeee have the diesso arrangedas to accurately give the desired spacing ofthe holes. Sucha punchis the subject of a copending application for patent and forms no part of the present inven tion.

As an alternative to having the hole b slightly behind the hole a, the same result can be obtained in the design of the bar by offsetting that hole in the tracker bar which governs the'operation of the rocker bar as illustrated in Figure 3. In Figure 3, the tracker bar [5 has a series of holes which are in line and which are designated 0. One hole (1 which is the hole for operating the rocker bar, is disposed out of linewith the other holes, so that with a record sheet traveling across the tracker bar the hole will be encountered before the hole d, with the result that the mechanisms energized through the holes c will operate a slightly ahead of the rocker bar.

It is desirable ,in mechanisms of this type to regulate the force with which the keys are operated. In the present invention, the force for operating the keys is drivedentirely from the rocker bar. I provide a simple adjustment through which the force with which the rocker bar is actuated may be adjusted. The tube 54 through which air is withdrawn from the valve unit C and from the pneumatics l2 communicates with a pneumatic 85 having a movable leaf and a fixed leaf 81. Air is withdrawn from the pneumatic 65 through tube 88. Inside the pneumatic 65 adjacent the exhaust port is a seat 69.. A tension spring 10 has one end attached to the movable leaf B and the other end of this spring is attached to a bracket Tl carried on a nut 12 which travels along a threaded shaft 13, this shaft having a knurled head 14 by means of which it may be turned. Movement of the shaft 13 in one direction increases the; tension onthe spring, while movement in the opposite direction decreases tension on the spring. If the spring 18 is adjusted so as to exert relatively little tension, the leaf 88 of the pneumatic 65 will move more freely than if there is a considerable tension. If there is considerable tension, pneumatic 65 will tend to remain open when air is being exhausted from the pneumatics l2 causing the pneumatics I2 to operate with considerable force. If, however, the tension of the spring is relatively light,-the pneumatic 66 will collapse, tending to choke ofi or restrict the suction to the pneumatics I2, with the result that it tends to reduce the force with which the rocker bar is actuated.

The suction line 68 leads-from the pneumatic 85 to the control unit B, entering a chamber (see Figure 4) in the casing B. fAbove the chamber'l5 isa second chamber I6. Air is withdrawn from the chamber 16 through a passageway (not shown) communicating with a pipe 11 to which is attached a tube 18 leading to the vacuum pump. A port 18 establishes communication between the port 15 and the port 16. On" the upper side of the port I9 is a pouch 80 providing a valve for the port 19. From the back of the pouch, 80 there is a passageway 8| leading to the under side of a second pouch 82, which pouchis biasedby a spring 83 to normally close the passage 8|. A port 8! leading to atmosphere also leads to the under side of the pouch 82. From the upper side of the pouch 82, there is a passageway 82a leading to a valve chamber 82b in which is a valve 85 having pouches for operating it. This system of valves is part of the system through which the selector mechanism and the rocker bar is prevented from operating while the record sheet is being rewound. Action cut-out valves of this nature are "at present used in pneumatic mechanisms and are well under- .82 whereupon atmospheric air entering through the passage 84 raises the pouch 82 against the pressure of its biasing spring 83, permitting atmospheric air to flow through the passage 8| back of the pouch 80. Since a vacuum or reduced pressure exists in the chamber 16, the pouch 80 is forced down against the top of the port 19, shutting off the suction line 68 to the rocker bar circuit. When valve 85 is in the position shown in Figure 4, the spring 83 holds the diaphragm 82 over the end of passage 8|, closing this passage against atmospheric air. A bleeder cup 81- enables the air to be exhausted from the passage 8| into the vacuum chamber 18, so that the pouch 80 is held off the top of the port 19, thereby allowing the suction passage from the chamber 15 through the port 79 to the chamber 16 to be opened. The vacuum pump is the vacuum pump A previously described. The cut-out valve mechanism herein described is also the one which is effective for preventing the operation of selector pouches during the rewinding movement of the record.

Certain operations of the typewriter have to be effected under some conditions before the operation of a typewriter letter key. For instance, if

it is desired to write a capital instead of a small letter, the shift key has to be operated before the letter selector operates or simultaneously with the letter selector, but prior to the movement of the rocker bar. The power for actuating the shift key must be independent, therefore, of the power which operates the character keys. Likewise, the operation of the tab key has to be efiected at a time whenthe character keys are not in motion. The power for operating the tab keys is, therefore, also preferably separate from the rocker bar. Both the operation of the shift key and of the tab key, however, are under the control of the same record sheet as controls the operation of the selector and the rocker bar. In Figure 9, the shift key and tab key-operating devices and the controlling circuits therefor are schematically illustrated. In this figure, 9|] designates the bar on the shift key of a typewriter or other mechanism and 9| is the bar of a tab key. Clipped to the bar 90 is a connectirrg' rod 92 the lower end of which is hookedinto the top of a penumatio 93. which pneumatic is anchored on a support 94 in the frame 2. A similar necting rod 95 is clipped to the tab key bar 9 fuand is hooked to the top of a pneumatic 98 also suported on the member 94% Leading from the bottom of. the pneumatic-93,

is a connection!" to which isattached a tubefill' leading to a nipple 98 alsdri' lounted in the valve" trom those which are described in connei'ztioii It will be understood that the vatye 6 with Figure '4. Leading from the bottom of the pneumatic 96 is a connection I to which is attached a tube IOI leading to a nipple I02 also opening into the, valve casing B.

The nipple 99 opens into a pneumatic valve chamber I03 in which is a movable valve member I04 over a port I05 leading to a chamber I06. The chamber I06 communicatesthrough a devious passage (not shown) to a suction line I0'I connected to the vacuum pump. The passageway from the chamber I06 to the line I0'I may include a valve system similar to the valve 00 or may utilize this same valve so that the shift key and the tab" key will not operate on the rewind of the record. The top of the valve chamber I03 has a port I08 communicating with a passage- -way I09 that opens to atmosphere. Below the valve I04 is a pouch IIO. ,Air can be admitted to the under side of this pouch I I0 through passage III in which is a nipple to which connects a tube II2 leading to an appropriate opening in the tracker bar I5. A bleeder cup II3 establishes communication between the passage III and the suction chamber I06.

in FigureQ. When an opening e inthe record sheet X passes over the proper opening in the tracker bar, air is admitted through the tube I I2 to the under side of the pouch IIO. Since there is a vacuum above the pouch, the pouch H0 is lifted or bellowed upwardly, raising the valve I04, closing the port I08 against incoming atmospheric air, and at the same time establishing communication from the chamber I03 through mechanical construction of the valve is in all respects similar to the mechanical construction of the valve 56 shown in Figure 5 where the parts are shown on a larger scale. When the valve I04 is thus operated, chamber I03 communicates with the vacuum chamber I06 and air is exhausted through the tube 98 from the pneumatic 93, collapsing this pneumatic 93 to operate the shift key bar 90. Since the shift key has to be depressed before the operation of a character key on the typewriter and must remain down until after the rocker bar has completed its'power stroke, the opening e is of considerably greater length in the direction of travel of the record than are the holes, such as the hole a for operation of the selector or the holes I) for operating the rocker bar. The efiect of a single long hole is obtained by a plurality of closely spaced small holes as shown in Figure 9. In Figure 9 it will be noted that the beginning of the long hole e is ahead of the opening a, and that the last of the long hole e is just slightly back of the hole I) in the record,

so that the desired time relation in the operation of the several pneumatic circuits is obtained. It

will, of course,be understood that instead of having a long hole e in the record, a corresponding result can be obtained by having the long hole in the direction of travel of the record in the tracker bar. 7 V

The valve system for the pneumatic 96 is substantially the same as that described. The nipple I02 opens into a passageway II5 leading into a valve chamber II6. In this chamber is a valve I I! overa port I I8 leading to the vacuum cham- 70 her I06. The valve chamber II6 has a port H9 in the top thereof opening to passage I09l1eading *t'o the atmosphere. Below the valve Ill is a pouch I20. A passageway I2I leads from the under side of this pouch to a tube I22 connected 76 to the proper opening in the tracker bar I5.

Normally, the parts are in the position shown the port I05 to the exhaust chamber I06. The

There is a bleeder cup at I23 between the passage I2I and the vacuum chamber I06. When the long hole or series of closely spaced holes fin the rec- I 0rd sheet X moves over the proper opening in the tracker bar, air is admitted to the tube I22 and from there to the under side ofthe pouch I20, causing this pouch to lift up and raise the valve In, closing the port 'II9 to atmosphere tion chamber I06, whereby air can be exhausted through the tube IOI from the pneumatic 96 to collapse the pneumatic and operate the tab key bar 9I. When the opening has passed the tracker bar opening, the admission of further atmospheric air is cut off, the air in the passage I2I is exhausted through the bleeder cup I23, pouch I20 drops to its original position, valve. I I1 returns to the position illustrated in Figure 9, and atmospheric air can flow into the pneumatic 36 to expand it.

The mechanism as described provides a pneumatic unit wherein the power for actuating all of the character keys on the typewriter is furnished by a common pneumatic operating device, thus eliminating the necessity for a separate pneumatic for each character key. The selector mechanism is simple in its construction; comprising essentially a number of pouches. The selector mechanism itself is extremely compact and can be condensed into a small space, and the space required for the rocker bar mechanism is small. The action, while extremely simple, is positive. All of the character keys are operated with the same degree of force and the forcecan be ad- ,and connecting the valve chamber I I6 to the suc- 'justed to suit the operator. The mechanism i does not in any way interfere with the operation of the typewriter manually as the provision of the connector members I and the resilient connectors 8 does not materially change the touch of the typewriter. The operation of the mechanism is faster than mechanisms wherein a separate pneumatic is employed for the operation of each character .key, and the speed is further accelerated by the use 'of a primary-secondary valve combination in the unit C for controlling the operation of the rocker bar. It would, of course, be entirely feasible to use only a single valvein the rocker bar action, corresponding, for instance, to the valve I05 of Figure 9, but such an action is more sluggish than where'a secondary valve is provided in combination with a primary valve. Where the primary-secondary valve arrangement is employed, the primary valve receivingthe impulse of air through the tracker bar, acts, ineffect, as a trigger for'operatlng the secondary valve or valveswhile the exhausting of the fluid from the pneumaties I2 is taken care of in the secondary valve, thus providing an extremely rapid and snappy action.

Because the action of the rocker bar is faster, the record sheet can move faster and the typewriter can be operated at a high rate of speed. As a matter of fact, the principal limitation on the speed is now the rapidity with which the type bars fall back into the type basket after they have It will be noted in Figure 2 that the connector 8 is flexed upwardly from ahorizontal position; This flexing is determined to be such that when the key has been pressed one-half the distance of its full travel, the member 8 will be straight and when it moves past this half way point the flexing of the rod will be downward. By flexing to the character keys while operating the shaft and tab keys independently of the rocker bar mechanism, the proper timed relation for the opera tion of all keys can be secured. All of these relations can be determined in the punching of the record, and the record perforator in turn can be such as to cause the various units to operatein proper sequence. Since the power for operating all of the, keys is derived from four relatively small pneumatics, two forthe rocker bar, one for the shift key and one for the tab key,

the capacity of the pump required to operate the. mechanism is relatively small, very little air being passed through the selector or pouch box unit itself.

While I have illustrated and described specifically a particular embodiment of my inven tion, it will be understood that this is by way of illustration and that various modifications and changes may be made within the contemplation of the following claims.

I claim: i

l. A pneumatic action comprising a plurality of elements to be selectively operated, a tracker bar having openings therein, means for moving a record over the tracker bar, a record-controlled main operating member for transmitting motion to any one of said elements, a plurality of pneumatic pouches corresponding to the elements to be actuated, and means actuated by the pouches for bringing an element to be operated into driving engagement with the main operating member.

2. A pneumatic action comprising an actuating member, a plurality of motion transmitting ele ments having terminal portions for engagement with, the actuating member, record-controlled means for controlling the operation of the actuating member, pneumatic means for selectively moving said motion transmitting elements into and out of position where the terminal portions thereof are engaged by the actuating member, and record controlled means for controlling the operation of said pneumatic means.

3. A pneumatic action comprising an actuating member, a plurality of motion transmitting elements having terminal portions for engagement with the actuating member, pneumatic means for selectively moving said motion transmitting elements into and out of position where the terminal portions thereof are engaged by the actuating member, record'controlled means for controlling the operation of said pneumatic means, and record-controlled means for operating the actuating member in timed sequence with respect to the operation of said pneumatic means.

4. A pneumatic action including a rocker bar, a plurality of motion transmitting elements having terminal portions for engagement with the rocker bar, pneumatic means for selectively moving said motion transmitting elementsinto and out of position where the terminal portions thereof are engaged by the rockerbar, means for actuating the rocker bar, a record and tracker bar for controlling the operation of said pneumatic means and for also controlling the operation of said rocker bar actuating means, the tracker bar and record having correlated openings therein so disposed that the rocker bar is actuated slightly after the operation of said pneumatic means.

5. A pneumatic action comprising a tracker bar having a plurality of openings, a plurality of pneumatic pouches and passages leading from one side of each pouch to a tracker bar opening, a suction pump, the other side of said pouches being connected with the suction pump, a connecting rod operatively associated with each pouch to be operated thereby, link members with which the connecting rods are attached and which are moved by operation of the pouches from a normal position to an out-of-line position, an actuating member for engaging those links which are moved to the outof-line posi tion, and means for operating the actuating member in timed relation to the movement of device having a plurality of movable key bars,

of a depending hook-like member attached to bar, and pneumatically controlled means for actuating the rocker bar in timed relation to the movement of the hook-like members.

7. The combination with a typewriter or like device having a plurality of movable key bars, of a depending hook-like member attached to each key bar, said hook-like members being arranged in line andterminating in a substantially common level, a rocker bar movable with respect to said hook members, pneumatically operated means for selectively moving the hooklike members into the path of travel of the rocker bar, and means for actuating the rocker bar, said last named means and said pneumatically operated means both being record controlled.

8. The combination with a typewriter or the like having a plurality of key bars adapted to be selectively operated, an operating mechanism comprising a series of links attached to the several key bars having terminal portions thereon for cooperation with an actuating mechanism, an actuating mechanism for engagement with the terminal portions of said links, a recordcontrolled pneumatic selector for selectively moving the terminal portions of said links into and out of position to be engaged by said actuating mechanism, and record-controlled means for operating the actuating mechanism in timed relation to the operation of the selector.

9. The combination with a typewriter or the like having a plurality of key members to be selectively operated in succession, a common actuating device for all of said keys, record-controlled means for controlling the said actuating device, and a record-controlled pneumatic selector through which the keys are selectively operated in succession by said actuating device.

10. The combination with a typewriter or the like having a plurality of key members to be selectively operated in succession, a pneumatically operated key actuating device for all of said keys, a record controlled pneumatic selector through which the keys are selectively oper? ated in succession by said actuating device, and adjustable means for varying the pressure applied by said actuating device.

11. The combination with a typewriter or the like having a plurality of key members to be selectively operated in succession, of a key actuating device for all of said keys, a suction pump, said actuating device" havingapneumatics connected with thesuction .for'operating it, a record controlled pneumatic selectorthrough which the keys are selectively operated in succession by said actuating device, and an adjustable pneumatic governor operatively connected between the pump and thepneumatics for said key actuating device for regulating the force with which the actuating device is operated.

12. A pneumatic selector mechanism of the class described, comprising a chamber having a plurality of separate pneumatic pouches therein and means for exhausting air from the chamher, a plurality of rods passing through a wall of the chamber, means for transmitting motion from the individual pouches to the individual rods, and means for preventing the leakage of any substantial volume of air into the chamber around the rods, said means comprising a metal plate sealed against a wall of the chamber and having a plurality of openings therethrough in which the rods have a sliding fit.

13. A pneumatic selector mechanism of the class described, comprising a chamber having a plurality of separate pneumatic pouches therein and means for exhausting air from the chamber, a plurality of rods passing through a wall of the chamber, means for transmitting motion from the individual pouches to the individual rods, and means for preventing the leakage of any substantial volume of air into the chamber around the rods, said means comprising a metal plate sealed against a wall of the chamber and having a plurality of openings therethrough in which the rods have a, sliding fit, said plate comprising a graphite bronze.

14. The combination with a typewriter or the .like having a plurality of key bars to be selectively operated in succession, of link members attached to and suspended from the key bars, said links terminating in abutments for engagement with an actuating device, an actuating device, a selector for moving said links selectively into position to be engaged by said actuating device, said selector having a plurality of operating rods and flexible links connecting the operating rods and said first mentioned links.

15. A- pneumatic selector action intended for use as. "a pilot mechanism in effecting, the operation of multiple key devices comprising a plurality of supporting members, each member having a row of pneumatic diaphragm pouches thereon, the pouches of each row being laterally offset from those of the other rows, a finger operatively associated with each pouch, the end of each finger projecting above the plane of the tops of the supporting'members each finger having a motion transmitting rod attached thereto, movable members actuated by said motion transmitting rods, a record controlled tracker bar having a plurality of openings therein, and an air ductvleading directly from each pouch to a, tracker bar opening.

GEORGE W. CARLSON. 

